.tree {
    min-width: 400px;
}
.tree a {
    display: inline-block;
    width: 100%;
    color: #1b2b40;
    text-decoration: none;
    font-size: 20px;
    line-height: 25px;
}
.tree ul{
    list-style-type: none;
    padding-left: 40px;
}
.fold.active .foldContent {
    display: block;
}
.fold:not(.active) .foldContent {
    display: none;
}
.tree .unfold > a:before {
    content: '- ';
}
.tree .fold > a:before {
    content: '+ ';
}
.tree .fold.active > a:before {
    content: '- ';
}
.tree ul li.unfold:hover, .tree ul li.fold span:hover, .tree .fold a:hover {
    color: #ccc;
    background: #1b2b40;
}

